A flexible printed circuit board (FPC board for short) is manufactured by adopting an insulating substrate such as a flexible polyester film or polyimide and combining the line formed on a copper foil by etching, and has high reliability and excellent flexibility. It can be freely bent, wound and folded, and can be arranged according to the spatial layout requirements and arbitrarily move and expand and contract in three-dimensional space, so as to achieve the integration of component assembly and wire connection. The use of the FPC board can greatly reduce a volume of a speaker, and is suitable for the development of the speaker in the direction of high density, miniaturization, and high reliability. Therefore, FPC boards have been widely used in aerospace, military, mobile communications, laptop computers, computer peripherals, handheld computers, digital cameras and other fields or products.
In the related art, when the FPC board is applied to the speaker, a pad located on the FPC board and electrically connected to the voice coil is not on the same side as an external pad of the speaker, such that the FPC board often needs to use a double-sided board design, and the pad connected to the voice coil and the external pad of the speaker are conducted through a via hole. However, the double-sided board is relatively expensive.